Your Selection for that Extension Could Be Dangerous. 

Should you use an extension cord or multiple outlet strip with a portable or window air conditioner?  The general easy answer is NO.  Window air conditioners and extension cords don't mix!

In fact, the heat produced by an overloaded extension cord can lead to sparks and a fire.  An industry group that keeps track of these things, the Electrical Safety Foundation International (ESFI), reports about 3300 homes catch fire due to the misuse of electrical extension cords and strips each year, resulting in deaths and injuries.

Here are ways to prevent fires and stay safe when using portable air conditioners, and other major electrical appliances:

• Plug portable air condtioners directly into a wall outlet.  This recommendation comes from most manufactuers.  
• Look at the unit's power cord.  If you see any fraying or exposed wires, have an electrician repair the cord before using the unit.
• Plug the unit into a grounded outlet.  An electrician can confirm the outlet is grounded if you are uncertain.

More safety information about extension cords can be found by clicking here.